One major component of optical devices for detecting light may be photo-detectors. Generally, photo-detectors convert light into electrical signals. However, the conversion of light into electrical signals may be affected by disturbances from surroundings. For applications such as fiber optics communication system, the disturbances may induce bit error or to a lesser extent, may reduce the communication speed. For other sensing applications such as encoders and opto-couplers, the disturbances may produce noise, which may reduce sensitivity of the optical devices. Further, the disturbance from surroundings may be almost unavoidable for optical devices that are used in industrial settings. Even for consumer or home appliances, the issue of disturbances may become more serious.
Additionally, the disturbance may add burdens to the package design. Package designers and housing designers may be required to add shielding or may impose design requirements to ensure that the disturbance received in the optical devices are minimal. The task to meet those requirements may be difficult for some applications. For example, in fiber optic communication, the optical devices may be placed in locations that are susceptible to high noise. For optical devices that are used in industrial settings, the optical devices may be required to operate in a high noise environment. As users demand small compact devices, more and more devices may be packed into limited space resulting in higher disturbances for consumer use optical devices. Some efforts have been attempted to reduce the effect of such disturbances through packaging and shielding the optical devices. However, such efforts may have not been completely effective.